A method of forming filter cigarettes

ABSTRACT

A smoke filter is provided which is adapted to be combined with a tobacco rod to form a filter cigarette. The filter includes an elongated core piece of smoke impervious material, a first sleeve of thin perforated material encompassing said core piece, and a second sleeve of smoke impervious material encompassing said first sleeve and an end of the tobacco rod. The second sleeve has a portion thereof spaced from the first sleeve and cooperating therewith to form a first sleeve and cooperating therewith to form a first elongated annular passageway, one end of which communicates with the tobacco rod end. The perforations of the first sleeve form a core piece-encircling row which is in registration with a second elongated annular passageway formed by the first sleeve and an exterior portion of the core piece. The smoke passes at a high velocity from the first passageway to the second passageway through the row of perforations and impinges against the exterior portion of the core piece. The space between the first and second sleeves is formed by a short third sleeve interposed between the first and second sleeves. A method of forming the article is provided in which a multiple length filter is formed with said first sleeve being continuous and said third sleeve being applied as axially spaced portions around said first sleeve, after which the assemblage is severed into double length filter portions which are interposed between two cigarette portions and joined thereto by said second sleeve.

United States Patent Pinkham 1451 Feb. 1, 1972 [54] METHOD OF FORMING FILTER [57] ABSTRACT CIGARETTES A smoke filter is provided which is adapted to be combined [72] Inventor: Jesse R. Pinkham, Winston-Salem, NC. with a tobacco rod to form a filter cigarette. The filter includes an elongated core piece of smoke impervious material, a first [73] Asslgnee' sgg h Tobacw Company Wm sleeve of thin perforated material encompassing said core piece, and a second sleeve of smoke impervious material enl l Filed! 1969 compassing said first sleeve and an end of the tobacco rod.

[21] Appl N0: 876 237 The second sleeve has a portion thereof spaced from the first sleeve and cooperating therewith to form a first sleeve and cooperating therewith to form a first elongated annular [52] US. Cl. ..l3l/94, 93/] C, 13 l/l0.5 passageway, one end of which communicates with the tobacco is 1] f 05/ 13? 5 8 rod end. The perforations of the first sleeve form a core piece- [581 held of are l 3/1 C encircling row which is in registration with a second elongated annular passageway formed by the first sleeve and an exterior [56] Rderences Cited portion of the core piece. The smoke passes at a high velocity UNITED STATES PATENTS from the first passageway to the second passageway through the row of perforations and impinges against the exterior porgi g tion of the core piece. The space between the first and second 3,351,072 [1967 argumgtugin. H1 5 sleeves is formed by a short third sleeve interposed between 3O52'164 9/1962 Rowlands i i i i i 13 X the first and second sleeves. A method of forming the article is 1125917 11/1965 Stelzer ..-11111111111-....... .IIZIi51/94 ux Pmvided which ""iiiiPie ieiigih is imied wiii Said Primary Examiner-Samuel Koren Attorney-Pendleton, Neuman, Williams & Anderson first sleeve being continuous and said third sleeve being applied as axially spaced portions around said first sleeve, after which the assemblage is severed into double length filter portions which are interposed between two cigarette portions and joined thereto by said second sleeve.

2 Claims, 8 Drawing Figures A METHOD OF FORMING FILTER CIGARETTES BACKGROUND OF THE INVENTION Various filter cigarettes have heretofore been produced; however, because of certain design characteristics they are beset with various production and/or operational shortcomings such as (a) a plurality of component parts are required whichare costly to produce and difficult to assemble, (b) assembly of the component parts is not compatible with techniques which are commonly used in the cigarette-making industry, (c) the pressure drop across the filter during smoking is nonuniform and inordinately high, and (d) the filter is ineffective in removing liquid and solid particles from the smoke.

SUMMARY OF THE INVENTION It is an object of this invention to provide a method for making a filter the component parts of which may be expeditiously formed and assembled by automatically operated mechanical means.

It is a still further object of this invention to provide a method for making a filter which can be produced at a rate which is compatible with the production rate of the tobacco rod.

Further and additional objects will appear from the description, accompanying drawings, and appended claims.

In accordance with one embodiment of the invention a filter cigarette is provided which includes a tobacco rod, a smoke impervious core piece disposed in abutting aligned relation with respect to one end of the tobacco rod, and a mass of absorbent filter material disposed in abutting aligned relation with respect to the downstream end of the core piece. Overwrapping the core piece and mass of absorbent material is a first sleeve formed of thin perforated film. Encompassing the first sleeve and the abutted end of the tobacco rod is a second sleeve formed of tipping paper. Portions of the first and second sleeves are disposed in spaced relation and cooperate with one another to form an annular first passageway, one end of which is in communication with the tobacco rod end. The exterior of the core piece has a cylindrically shaped upstream end, a cylindrically shaped center section of lesser diameter than said upstream end, and a splined downstream end. The perforations formed in the first sleeve are arranged in a sleeveencircling row which is in registered relation with the center section of the core piece. The first sleeve cooperates with the center section and splined end of the core piece to form a second passageway. The smoke from the tobacco rod initially flows through the first passageway and then passes at a high velocity through the perforations into the second passageway and impinges against the exterior of the core piece center section casing the liquid and solid particles entrained in the high velocity smoke to be deposited thereon.

DESCRIPTION For a more complete understanding of the invention reference should be made to the drawings wherein:

FIG. 1 is an enlarged fragmentary longitudinal sectional view of a filter cigarette embodying a preferred form of the improved filter.

FIG. 2 is a sectional-view taken along line 22 of FIG. 1.

FIG. 3 is a sectional view taken along line 3-3 of FIG. 1.

FIG. 4 is a perspective view of a rod from which a plurality of core pieces are formed.

FIGS. 5 and 6 are similar to FIG. 4, but showing the improved filter in various successive stages of assembly.

FIG. 7 is similar to FIGS. 4-6, but showing a dual length assembly in which two tobacco rods are affixed to opposite ends of an unsevered double length improved filter.

FIG. 8 is similar to FIG. 1, but showing a modification of the improved filter cigarette.

Referring now to the drawings and more particularly to FIG. I. a filter cigarette 10 is shown which includes a tobacco rod 11 having a core 12 of compacted shreds of blendedtobacco encompassed by a sleeve 13 of conventional cigarette paper. The initial length of the rod may vary as desired.

To the downstream end of the rod 1] is affixed the improved filter 14. A preferred form of the filter 14 is shown in FIG. I and comprises an elongated core piece l5 which is formed of a smoke impervious material (e.g., polystyrene), a plug or mass 16 of absorbent filter material (e.g., cellulose acetate), a first sleeve 17 formed from a web of thin perforated film (e.g., Mylar having a thickness of from about 0.0005 inch to about 0.002 inch), and a second sleeve 18 formed from a web of tipping paper or the like.

The core piece 15 may be formed by extrusion coupled with after-forming, by injection molding, or by various other wellknown methods. Likewise, the type of material utilized in making the core piece may vary over a wide range provided it is smoke impervious, inexpensive and lightweight, and does not deleteriously affect the smoke.

In the illustrated embodiment, core piece 15 has a cylindrically shaped upstream end section 15a, a cylindrically shaped center section 15b of lesser diameter than section 15a, and a splined downstream end section 15c. The overall length of the core piece 15 is approximately 15 mm. The outside diameter of the end section 1511 is approximately 0.024 inch less than the outside diameter of the tobacco rod I1 The center section 15b, in turn, has an outside diameter which is about 0.020 inch to about 0.030 inch less than the outside diameter of the end section 1511.

As seen in FIGS. 1 and 3, the splined end section 15c is provided with four symmetrically arranged flutes or channels 20a, b, c, and d which are separated from one another by a like number of elongated ribs 21a, b, c, and d. The ribs, in the illustrated embodiment, are relatively wide and the outer surface thereof is of arcuate configuration and provides an effective support for the first sleeve 17. It will be noted in FIG. 3 that the radial dimension of each flute 20ad from the interior surface of sleeve 17 is greater than the radial distance of the exterior of core piece center section 15b from the said sleeve. The number, size, and configuration of both the flutes and ribs may readily vary from that shown without departing from the scope of this invention.

First sleeve 17 snugly encompasses and is secured to core piece end section 15a and the arcuate rib surfaces of end section 150. Sleeve 17 is provided with a row of perforations 22 which are arranged in encircling relation with respect to the center section 15b of the core piece. The number of perforations comprising the row may vary from 10 to 20 and the aggregate .area of the perforations should be about 0.0008 square inch. By reason of the perforation size, the velocity of the smoke when passing therethrough is materially increased. Because of the diameter differential between end section 15a and center section 1512 of the core piece 15, a portion of the sleeve 17 cooperates with the center section 15b to form a shallow annular passageway 23. Thus, the high-velocity smoke upon entering passageway 23 is caused to impinge against the exterior of center section 15b and deposit thereon liquid and solid particles entrained in the smoke. The downstream end of passageway 23 communicates with the upstream ends of the flutes 20a-d. The opposite, or downstream, ends of the flutes are in contact with the porous plug 16. The plug preferably has an outside diameter comparable to the outside diameter of the upstream end section 15a of the core piece and has an axiallength of approximately 10 mm. If desired, however, plug 16 may be omitted or may be formed of some other suitable material, such as a sintered mass.

Sleeve 17 encompasses both the core piece 15 and the plug 16 and retains same in abutting axially aligned relation.

The outer sleeve 18, which secures the filter to the end of the tobacco rod, is in spaced concentric relation with sleeve 17 and cooperates therewith to form an outer annular passageway 24. The upstream end of passageway 24 communicates with the tobacco core 12. The downstream end of passageway 24 is defined by a smoke impervious. annular spacer piece 25. The piece 25 has a thickness of approximately 0.0 I 2 inch and may be formed in a manner to be hereinafter described. It will be noted in FIG. 1 that .the spacer piece 25 is located downstream of the row of apertures 22. It is the apertures 22 which provide the communication between passageways 24 and 23.

FIGS. 4-7 show a preferred method of forming the improved filter cigarette 10. FIG. 4 shows an elongated rodlike element 26 which may be formed by extrusion followed by after-forming techniques well known in the forming art. Element 26 is preferably formed from a foam plastic material such as polystyrene. For ease of handling, the illustrated element 26 includes a multiple of six core pieces 15, each core piece being approximately 15 mm. in length. At each end of element 26 is formed a splined end section 15c. Intermediate the end sections 15: and arranged in alternately spaced relation are sections A and B. Section A consists of a double length cylindrically shaped end section Ba and section B consists of a double length splined end section 15c. Sections A and B are separated from one another by a single length cylindrically shaped central section 15b. The sections 15c formed at opposite ends of element 26 are likewise separated from the adjacent double length section A by the single length central section 15b.

Once element 26 has been formed, it is then cut into various segments which are then reassembled with double length plugs l6 of absorbent material to form an elongated (approximately I mm. in length composite rodlike unit 27, see FIG. 5. Unit 27 in the illustrated embodiment comprises a single length core piece 15, (approximately mm. in length), a double length plug 16' (approximately 20 mm. in length), a double length core piece 15 (approximately mm. in length), which includes a section A, a second double length plug 16', and a second single length core piece 15. The various component parts of unit 27 are retained in their axially align ed relation by a multilength sleeve 17 of thin perforated film. The perforations 22 of the sleeve 17' are in registration with the central sections 15b which form part of the unit 27. The length of unit 27 may vary from that shown without departing from the scope of the invention, and will depend upon the ease of handling by the automatic equipment utilized.

Subsequent to the formation of unit 27 double length spacer strips 25' are applied to the exterior of unit 27. The strips 25 are in registration with the double length plugs 16' and the splined end sections lSc in abutting relation therewith. Each strip 25' is formed from a web of thin film which is wrapped about the unit 27 until the desired thickness of material (approximately 0.0l 2 inch) has been attained. The unit 27 with the spacer strips applied is commonly referred to as a four-up assembly. The unit 27 is then severed along cut line X, see FIG. 6, so as to form two identical segments each consisting of a double length plug 16 and a pair of single length core pieces 15 disposed at opposite ends of the plug 16'. Each segment may be referred to as a two-up assembly. To opposite ends of the two-up assembly are positioned tobacco rods 11 and the abutting ends of the tobacco rods are secured to the two-up" assembly by a double length outer sleeve 18 of tipping paper, see FIG. 7. Subsequent to the outer sleeve 18' being applied, the assembled unit is severed along cut-line Y, so as to form two complete filter cigarettes.

The aforenoted steps in forming and assembling the improved filter cigarette may be readily accomplished with automatic equipment, the function and operation of which are well known in the cigarette-making industry.

FIG. 8 shows a modified form of filter cigarette I00 wherein in addition to the various components of cigarette 10, there is provided a third sleeve 28 which is interposed outer sleeve 18 and the perforated inner sleeve 17. In assembling the modified cigarette I00, sleeve 28 encompasses rodlike unit 27 subsequent to the double length spacer strips 25 having been applied thereto (see FIG. 6). Sleeve 28 serves a dual function;

(a) it provides added stiffness for the outer sleeve 18 (tipping paper) and thus reduces the possibility of the passageway 24 collapsing due to lip pressure during smoking, and (b) permits testing of the filter prior to the tobacco rod and tipping paper sleeve being affixed thereto. Thus, if by chance there should be a malfunction of the improved filter due to impro er assembly thereof, such a malfunction can be ascertained efore the tobacco rod is connected thereto, thereby reducing the loss by rejects of said rods.

While the improved filter has been described in relation to a cigarette, it may, of course, be utilized with a cigar, incorporated in a pipe stem, or embodied in a holder for cigarettes or cigars.

Thus, it will be seen that an improved filter cigarette and method of forming and assembling same have been provided which avoid the shortcomings long associated with filter cigarettes. The filter in question has a minimum number of component parts which are of simple, inexpensive construction. The filtering action of the improved filter is substantially uniform and effective.

lclaim:

1. A method of forming an impingement type filter cigarette from double length cylindrically shaped rods of absorbent filter material, a first web of thin perforated film, a second web of tipping paper, a third web of thin film, and an elongated core piece-forming rod of smoke impervious material, the latter having alternately arranged and longitudinally spaced thereon a plurality of double length cylindrically shaped first sections and a plurality of double length splined second sections, and single length cylindrically shaped third sections of less diameter than said first section, one third section being interposed adjoining first and second sections; said method comprising severing from the smoke impervious core pieceforming rod first and second segments, the first segment including a double length first section and a pair of single length splined second sections separated from said first section by said third sections, and each second segment including single length first and second sections separated by a third section; positioning double length rods of absorbent filter material in axially aligned abutting relation with the ends of one of said first segments and positioning the splined second section of one of the second segments adjacent each outer end of said absorbent rods to form an assemblage; encircling said assemblage with said first web to form a first sleeve whereby the perforations of said first web form rows disposed in registered encircling relation with respect to the third sections of said first and second segments, said first web coacting with said third sections to form shallow, axially spaced, annular, first passageways; encircling with said third thin film web axially spaced portions of said first sleeve in registry with the splined sections of said first and second segments and with the double length rods of absorbent filter material to form annular spacer pieces of predetermined thickness; serving the sleeved assemblage at the midlength of said first sleeve; positioning a tobacco rod in abutting aligned relation at each end of said severed first sleeve; encircling the assembled first sleeve, spacer pieces, and the abutting ends of said tobacco rods with said second web to form a second sleeve, said second web coacting with said first and third webs to form shallow, axially spaced, annular, second passageways, said first and second passageways being in registered relation and separated from one another by portions of said perforated first web; and serving the assembled unit at midlength of said second sleeve.

2. The method of claim I wherein the spacer pieces are formed by winding said third web about said first sleeve portions until the thickness of said spacer pieces is about 0.012 inch.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION' Patent No. 3,638,661 Dated February 1, 1972 Inventor) Jesse R. Pinkham It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Abstract, lines 8 and 9, delete "sleeve and cooperating therewith to form a first".

Column 1, line 50, "casing" should be causing Column 4, line 51, "the double" should be said double Column 4, line 53, "serving" should be severing Column 4, lines 62-63, "serving" should be severing a Signed and sealed this 25th day of July 1972.

(SEAL) Attest:

EDWARD MJLETCHERJR. ROBERT GOTTSCHALK Attesting Officer Commissioner oi Patents DRM Po-10S0 (10-69) uscoMM-Dc 60376-P69 U.S GOVERNMENT PRINTING OFFICE: [959 O366'33 

1. A method of forming an impingement type filter cigarette from double length cylindRically shaped rods of absorbent filter material, a first web of thin perforated film, a second web of tipping paper, a third web of thin film, and an elongated core piece-forming rod of smoke impervious material, the latter having alternately arranged and longitudinally spaced thereon a plurality of double length cylindrically shaped first sections and a plurality of double length splined second sections, and single length cylindrically shaped third sections of less diameter than said first section, one third section being interposed adjoining first and second sections; said method comprising severing from the smoke impervious core piece-forming rod first and second segments, the first segment including a double length first section and a pair of single length splined second sections separated from said first section by said third sections, and each second segment including single length first and second sections separated by a third section; positioning double length rods of absorbent filter material in axially aligned abutting relation with the ends of one of said first segments and positioning the splined second section of one of the second segments adjacent each outer end of said absorbent rods to form an assemblage; encircling said assemblage with said first web to form a first sleeve whereby the perforations of said first web form rows disposed in registered encircling relation with respect to the third sections of said first and second segments, said first web coacting with said third sections to form shallow, axially spaced, annular, first passageways; encircling with said third thin film web axially spaced portions of said first sleeve in registry with the splined sections of said first and second segments and with the double length rods of absorbent filter material to form annular spacer pieces of predetermined thickness; serving the sleeved assemblage at the midlength of said first sleeve; positioning a tobacco rod in abutting aligned relation at each end of said severed first sleeve; encircling the assembled first sleeve, spacer pieces, and the abutting ends of said tobacco rods with said second web to form a second sleeve, said second web coacting with said first and third webs to form shallow, axially spaced, annular, second passageways, said first and second passageways being in registered relation and separated from one another by portions of said perforated first web; and serving the assembled unit at midlength of said second sleeve.
 2. The method of claim 1 wherein the spacer pieces are formed by winding said third web about said first sleeve portions until the thickness of said spacer pieces is about 0.012 inch. 